John thomson



(No Model.)

J.V THOMSON. MECHANICAL Mov EMENT.

. Patented May 6, 1890.

THE News Pneus co., muro-mum, wn'snmcron, u. c.

` ilNiTEn STATES PATENT OFFICE.

JOHN THOMSON, OF BROOKLYN, NEV YORK.

MECHANICAL MOVEMENT.

SPECIFlGATION forming part of Letters Patent No. 427,448, dated May 6, 1890.

Appleman tied March 14,1890. serial No. 343,899. (Nomade.)

To @ZZ whom it may concern:

Be it known that I, JOHN THOMSON, a citizen of the United States, residing in Brooklyn, Kings county, State of New York, have invented certain new and useful Improvements in Mechanical Movements', of which the following is a specification.

This invention is a mechanical movement, and it particularly relates to the means for controlling the vibrating action of the beds or platens in the instance of horizontal stamping, embossing, or printing machinery, and is an improvement in and extension of the inventions for which Letters Patent of the United States were granted me as follows: Nos. 331,845 and 331,846, December 8, 1885, and No. 378,343, February 21, 1888.

The chief obj ect of this invention is to accomplish results practically uniform with those alreadyT attained, but with fewer and less complication of parts and increased smoothness and durability of action.

In the drawings, Figure l is a combined elevation and longitudinal center section showing the prior state of the art as disclosed in the patents cited; and Fig. 2 is a view similar to the first, developed on the same center lines, but showing my present improvement.

The desirable features in actions of this class will be more quickly comprehended by at once briefly describing the prior construction and operation as presented in Fig. 1. In the bed 1 0 of the frame 1l is mounted a main shaft 12, to which is attached on opposite sides the main gears `or crank-wheels 13, driven by the pinion 14. 'Fixed in the face of each gear-wheel is the crank or wrist pin 15. On opposite rocker-seats 16 of the frame rest the rockers 17 ,being a part of the bridge 18, to which is attached in the present case a platen 19. To the seat 2O on the lower side of the bridge is secured the bridge-cam 21, and in brackets 22, secured to the strut 23 of the frame, are mounted the pin 24 and friction-roll 25 thereon, which engage the bridgecam. Each of the trunnions 2G of the bridge and crank-pin are connected by main connecting-rods, as 27. To the face of each crank-pin is attached a dwell-cam 28, the cam or groove 29 of which, being on the inner side, is engaged by the friction roll and pin 30 31, mounted. on the face of the rod, the

crank-pin eyes of which 32 are slotted, as at 33. It we assume rotation of the gear, as indicated by the arrow 34, it will followvthat the horizontal portion 35 of the bridge-cam will first cause the platen to recede from the bed in a direct line to position 36. Then as the friction-roll 25 encounters the curved section 37 the rockers will be caused to both roll and slip differentially, changing the lateral motion of the platen into vibratory movement. Continuing, we find that the form of the upper section of the cam, as from the positions 38 and 39, is such as to practically effect rolling contact between the rockers and their seats, and when the point 39 of the cam reaches the center of the roll the face of the platen will be in the position indicated by the dotted outline 40, or at an angle of approximately forty-five degrees from the vertical face of the bed, while at the same time the crankpins will be at 41 and the trunnions at 42. It should be particularly observed that the action so far imparted to the platen has been at the maximum speed of the crank traveling in the circuit 43; but beyond this the dwell-cams will cease to be idle, and the roll, entering the curved portion 44 thereof, will now assume control and begin to decrease the motion of the platen, the crank-pins traveling forward in the slots of the rods. Vhen the position 45 of the dwell-cam is reached, the platen is at its extreme angle, as indicated by dotted outline 4G, or at sixty-eight degrees from the bed, and also at this time the extremity 47 of the bridge-cam intersects the bridge-cam roller and' the trunnion is at 45. Between the positions 45 and 49 of the dwell-cam its form is such that the connecting-rods and platen are vmaintained at a rest or dwell The continued movement of the crank simply reverses the operation just described. Therefore it is clear that fronrO to 41 or 50 to 51 the platen is swung back or forth at the full speed of the crank, but between 41 to 51 itis driven at a rate of motion less than that of the crank, an d, furthermore, that such change of motion and conditions in the platen are due to the intervention of the said dwell-cams.

It may be here stated that an extreme angle in the platen greater than siXty-five degrees to seventy degrees from the vertical is rather objectionable than favorable to rapid IOO feeding, while the hand should be clear of the platen when the angle is about thirty-five degrees to forty degrees; hence the more rapidly the platen can be swung to the least practicable feeding angle the greater will be the available time thereafter. So, too, it becomes more convenient to attach apparatus to the machine in which the most efficient operation will devolve upon the greatest available space between the bed and platen for the longest period of time. In other words, this is but a phrase of the common problem-space and time. 1

Passing' to Fig. 2, the preceding-described operation of Fig. l refers in every particular to this illustration in so far as relates to the positions 50 to 4l and 50 to 5l of the crank, to 40 ot' the platen, 4t2v of the trunnion, and 35 3S 39 of the bridge-cam; but it will be seen that the dwell-cams, their rollers and pins, and the slots of the rods are dispensed with entirely,.the eyes of the rods being bored to the diameter of the crank-pins and secured by an ordinary washer, as 52. In the bridgecam, however, beyond point 39, the form is changed from that of Fig. l, and this alone constitutes my invention.

Now, bearing in mind the several points in the operation as they have successively been pointed out-' the crank-pin at 4l or 5l, the platen at 40, the point 39 of the bridge-cam coincident with the center of the roll 25--it follows that by thus simply curving the nph per section of the bridge-cam inward toward the bridge, as from 39 to 53, the consequence of this will be to cause the rockers, as 17, to slip upon the rocker-seats, (as see the double arrow 54,) and hence will swing the platen at a rate of speed differential to that of the crank, the trunnions acting as an axis.

As shown in the present illustration, the development of the bridge-cam from 39 to 53 is such that the extent of this slip shall cause the platen to swing to the same extreme angle-sixtyeight degrees-as in the primary instance; but as the connecting-rods must now constantly move with the cranks the center of the trunnions will be carried farther outward, orto the position 55. This will also be the case in the instance of the platen, (as compare the lower edges thereof at 5G 57.) The conditions determining the form of the cam froln 39 to 53, as here shown,arc thatthe platen shall be cumulatively brought to or from the positions 40 to 46 at a rate of speed less than that of the cranks while they are passing between 58 to 4l or 5l, and this for the rapid operation of heavy masses is the theoretically best design; but it will be evident to mechanicians that this may be modified even to the extent of maintaining the platen at a uniform angle during a portion of the movement of the crank, or to reverse the conditions described, or to obtain a dwell by this simple expedient alone.

While this design adds nothing to the expense of construction in the part itself, it nevertheless not only accomplishes the same results as in the more complicated and expensive arrangement, but of even more importance is the fact that thereby both the smoothness, speed, and durability of the action are greatly enhanced.

I. A bridge-cam having upper and lower lateral extensions,in combination with the rocker and rocker-seats and friction -roll suitably mounted, the form and construction of the upper extension of the cam being sueltas to cause the rockers to slip upon their seats at a rate of speed differential to that of the crank, sub, stantially as described.

2. The combination,with the frame having a frictional roll, of a bridgecam having a curved portion and two end portions extending in opposite directions, substantially as described.

3. The combination, with the rocker-seats and bridge rocking thereon, of a friction-roll suitably mounted and engaging a bridge-cam, the said cam having a curved intermediate portion from which extends another curved portion of'shorter radius than the intermediate portion and a straight portion, substantiall y as described.

4. The combination, with the rocker-seats and bridge rocking thereon, of the crank-pin and connecting-rod between the crank-pin and bridge, and a friction-roll suitably mounted4 and engaging a bridge-cam, said cam having an intermediateportion and two end portions extending in opposite directions, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN THOMSON.

Witnesses:

EDW. K. ANDERTON, JOHN MCKINNON.

IOO 

